The AlternationCount and AlternationIndex properties of controls inheriting from ItemsControl allow setting property values that alternate across the collection of items.

The AlternationCount property dictates how many unique styles you alternate between. The most common value is 2, indicating that every other item has a particular style. In the example below, we use these properties to set up an alternating background color.

We set an ItemContainerStyle because we want to set a property for a given ListBoxItem. We then set the Background of each item to derive its value from the AlternationIndex property of the item. The AlternationConverter is used to convert this index, 0 or 1, into a SolidColorBrush.